During voting, the power play will revolve around China, Japan and the US, while the European Union could also flex its muscle

China Does not have its own bloc. But its image as a regional dealmaker might swing votes for Margaret Chan from several African and Asian countries after the first round. Five Eastern Mediterranean countries might also be persuaded to vote for Dr Chan, if there is no strong contender

Japan Asia has eight votes on the executive board, five from the western Pacific where contender Shigeru Omi has been re-elected as regional director for a second three-year term. With three Asians running, the votes may be split between Dr Chan and Dr Omi

United States Holds its cards close to its chest. It is understood that the US vote was key to the election of Lee Jong-wook against Belgium?s Peter Piot in 2003

Europe Usually votes as a bloc, with eight countries on the executive board. In the initial round their votes will be split among the European contenders including Finland?s Pekka Puska, Iceland?s David Gunnarsson and Turkey?s Tomris Turmen